Depressible platform



H. R. SIMPSON.

DEPRESSIBLE PLATFORM.

APPLICATION FILED IAIIfIs. 1922.

CIC)

Patented Nov. 7, 1922.

Patented Nov. 7, 1922.

HIRAM R. SIMPSON, OF SAN FRANCISCO, CALIFORNIA.

DEPRESSIBLE PLATFORM.

To all 'ic/1,0m t may concern.'

Be it kno-wn that I, HinAM R. SIMPSON, a citizen of the United States, and a resident of San Francisco, county of San Francisco, and State of California, have invented a new and useful Depressible Platform, `of which the following is a specification.

The present invention relates to improvements in depressible platforms and its particular obj ect is to provide convenient means for raising and lowering a section of a floor relative to the surrounding area. Such depressible platforms are used for various purposes, especially in connection with bank vaults, and a particular advantage of my device is that it can be handled without the application of much force, and that it has suitable spring means associated therewith which automatically assist in the raising of the platform, while this spring means is vrendered inactive during the time the platform is in its lowermost position.

With these and other object-s in view l have illustrated the preferred form of my invention in the accompanying drawing, in which Figure 1 illustrates Aa vertical cross section through my device along line 1 1 y vof Figure 2; Figure 2 a top plan view of the same, the cover of the platform being removed, and Figure 3 a sectional detail view of a spring arrangement adapted to aid in the raising of the platform. While I have shown only the preferred formof my invention, it should be understood that various changes or modifications may be made within the scope of the claims hereto attached Without departing from the spirit of the invention.

Referring to the drawing in detail, it will be seen that a pit (l) is provided in the ioor (2), which s assumed to be of concrete, and that a movable platform (8) consisting of'a metal cover (f1) resting on a plurality of transverse angle bars (6) is supported over the pit on links (7) and (8) forming toggle joints. Two pairs of these toggle joints are provided, one joint for each corner of the platform. The lower ends of the lower links (7) are pivotally supported on pins (11) secured in any desired manner in the walls of the pit so that each two of them forming a pair are axially alined. The upper ends of the upper links (8) are pivoted to the transverse rods (12) disposed in parallel relation to the pins (11) and supporting the two ends of the platform. The

`of which entends a. rod

free ends of the links (7) and (S) are pivoted to each other by means of pins (13). bv means of which the links are actuated. i .l

Considering the .first pair of links, that is the ones on the left hand side in the drawing, it 'will be seen that normally the lower link (7) is in a rerticalposition, while the upperlink (8) slaiits somewhat to the right. r1`he pin has a third link (111) attached thereto, the free end (16) of which can be actuated by a lever (17) pivotinT on a stud (18). It will be seen that wheii the lever (17) is pulled to the left the link (14) will actuate the pin (13) to revolve around the pin 11) .so as to turn the link (7) into the position indicated in dotted lines, the nin at the same time carrying the link L(8) with it so that the left hand portion of the platform is lowered.

The motion ofthe left hand pin (13) is transmitted to the right hand pin hv means of a lever (19) pivot-ally supported on the transverse shaft 1t will be noted that on the right hand side the link (8) of the togglel joints slants toward the left. The two pins (18) areconnected to the ends of the arms (22) and of the lever (19) by means of connecting members (24) and 2G), and it will be readilyv seen that if the links (7) of the left hand side revolve to the right, the motion of its pin (13) will be transmitted to the pin (13) on the right hand side through the lever (19) and the connecting members (24e) and (26), but in such a manner that the right hand side pin (13) revolves to the left as indicated in dotted lines, thereby lowering the right hand side of the platform simultaneously with the 'left hand side. L

To facilitate the raising of the platform. which ofcourse is brought about by manip-A ulating the lever (17) in the opposite direction, l provide the device i cylinder (28) through the closed end (29) (31) provided with a spring (32) confined between the plunger (33) at the end of the rod and the closed end (29) of the cylinder, The cylinder itself is pivotally secured as shown at (341) to a bracket (36), while the end of the rod (31) is pivoted to a rounded body portion (11) of the lever (19) in such a manner that when the lever (19) is turned a bend (412) in the rod (31) will allow its end pivot (43) to pass around the shaft (21) so as to pass its center. When in this position the spring (27) comprising a (B2) is rendered inactive due to the fact that the shaft (2l) lies within its line of draft, but when the lever (i9) has been turned slightly in an effort to raise the platform, the sjnint,r will become active and automatically perform a part of the work.

The operation of the device will be readily understood. 1When it is desired to lower 'the platform the lever (17) is pushed toward the left, as indicated in dotted lines, whicl'i will cause the two links (7) to turn on the transverse rods while the links (S) follow this motion so as to lower the platform. During` this operation the end of the rod of the springt arrangement will be 'arried around the shaft (2l) so as to set the spring. `While in this position the spring' although under tension isnot effective because the shaft (2l) lies within its line of action. llllhen the lever ('l) is pushed to the right the links will revolve on their respective rods in -the opposite direction causing the lever (i9) to turn, and as soon asthe end (4:3) of the rod has passed around the shaft (2l) the spring' will become operative and assist in raisinpY the platform.

fin adjustible stop is provided in operative proximity to each pin (13) and consists ot a screw (20) the head of which limits the motion of the link ("1" so that the height of the platform in its uppermost position can be adjusted.

l claim:

l. A depressible platform having; two coacting toggle joints supportingrI the same, meansfor actuating` one of the toggle joints and means for transmitting the motion of the first joint to the second, whereby the platform is lowered or raised, said last means comprising a lever pivotally mounted between the two joints and pivotal connecting,r links between-the knuckles of the oints and the arms of the levers7 and having spring means associated therewith for aiding in raisingthe platform.

2. A depressible platform having; two coacting` toggle joints supporting the same, means for actuating one of the toggle joints and means for transmitting' vthe motion of the first joint to the seeond whereby the plat-- .form is lowered or raised, said last means comprising;` a lever pivotally mounted. between the two joints and pivotal connecting links between the knuckles of the joints and the arms of the levers, having spring means associated therewith for aiding' in raising the platform7 and means for rendering,r the spring' inactive when the platform is in one of its end positions. Y i A depressible platform having two coacting toggle joints supporting the same,

means for actuating one of the toggle joints and means for transmitting the motion of the first joint to the second, comprisinga lever pivotally mounted between the joints, f )perative connections between thev arms of the lever and the knuckles of the joints whereby the platform may be lowered and raised, and a springactuated connection between one side of the `lever and a stationary point for aiding in raising the platform, a bend being provided lin said connection allowing its far end to travel around the fulerum of the lever so as to renderthe spring inactive while the platform is in its lowermost position. l

HIRAM R. SIMPSON. 

